English 'tone' is not accepted for PT 'tom'. In my opinion (not native English speaker, though) is that 'tone' is more precise than 'shade' to describe a nuance of a colour whereas 'shade' would be better for a grade of grey (how dark/light is this on a grey-scale) or how deep/dark is a shadow. I'd appreciate correction from a native English speaker!
I am a native English speaker and with respect to color I would use tone and shade interchangeably. I acknowledge there probably is a distinction that a more artistic person might be able to distinguish. However, I believe the common English speaker (outside of an artistic background) would rarely perceive a difference in denotation or connotation between the words "tone" and "shade."
A shade is a variant of that color.
If you like a particular shade of blue, then you like a specific blue (such as navy or sky blue).
Tone is used to describe the parts of a color. Like a grey with a blue tone is a grey with more blue in it, creating a bluish grey. It's used very similarly with color as it is with speech, which may also have a blue tone (sad speech).
Still not accepted 10/14/17. Two friends are together and they are selecting makeup. It is between blue and green. I like that blue shade. Now if there were two different blue colors, then yes, one over the other would be I like that shade of blue. (I dated a fashion model -- been there, done that).
"Shade" is actually less accurate than "tone", yet tone is not accepted.
In color theory, "tone" has a specific meaning, is not synonymous with "shade", "tint" or "hue". In my opinion, it should be accepted as the primary answer.
A hue is a particular pure color value. A shade is a hue mixed with a quantity of black. A tone is a hue mixed with gray. A tint is a hue mixed with white.
Yes, many people will use color terminology interchangeably, but vernacular usages shouldn't be preferred to the exclusion of those that express widely accepted technical definitions.